Directories - tests could be more complete

[simongareste]

The Directories exercise can be solved using

server.route({ 
   method: 'GET', 
   path: '/foo/bar/baz/file.html',
   handler: function(request, reply) {
       reply.file('public/file.html');
   }
});

However, the aim of the exercise is to check if a file in /foo/bar/baz/ will be redirected to its equivalent in /public. Another test should be added, with a different file name.